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arXiv 0708.4045math.OA
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C* 代数包含的稳定秩

Stable rank for inclusions of C*-algebras

Hiroyuki Osaka

摘要:

当一个单位元\ca $A$具有拓扑稳定秩1(记为$\tsr(A) = 1$)时,我们知道对于一个非零投影$p \in A$,$\tsr(pAp) \leq 1$。然而,当使用$\tsr(A) \geq 2$时,通常是错误的。本文证明了:如果一个有单位的C*-代数$A$有一个$A$的有公共单位的单有单位的C*-子代数$D$,使得$D$有\PSP和$\sup_{p\in P(D)}\tsr(pAp) < \infty$,则$\tsr(A) \leq 2.$作为一个应用,设$A$是一个有$\tsr(A) = 1$和\PSP的单有单位的\ca,$\{G_k\}_{k=1}^n$有限群,$\af_k$从$G_k$到${\rm Aut}((...((A\times_{\af_1}G_1)\times_{\af_2} G_2)...)\times_{\af_{k-1}}G_{k-1}).$ $(G_0 = \{1\})$的作用,则$$ \tsr((... ((A\times_{\af_1}G_1)\times_{\af_2} G_2)...)\times_{\af_n}G_n) \leq 2. $$

英文摘要:

When a unital \ca $A$ has topological stable rank one (write $\tsr(A) = 1$), we know that $\tsr(pAp) \leq 1$ for a non-zero projection $p \in A$. When, however, $\tsr(A) \geq 2$, it is generally faluse. We prove that if a unital C*-algebra $A$ has a simple unital C*-subalgebra $D$ of $A$ with common unit such that $D$ has \PSP and $\sup_{p\in P(D)}\tsr(pAp) < \infty$, then $\tsr(A) \leq 2.$ As an application let $A$ be a simple unital \ca with $\tsr(A) = 1$ and \PSP, $\{G_k\}_{k=1}^n$ finite groups, $\af_k$ actions from $G_k$ to ${\rm Aut}((...((A\times_{\af_1}G_1)\times_{\af_2} G_2)...)\times_{\af_{k-1}}G_{k-1}).$ $(G_0 = \{1\})$ Then $$ \tsr((... ((A\times_{\af_1}G_1)\times_{\af_2} G_2)...)\times_{\af_n}G_n) \leq 2. $$

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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